Police are doing a good job tackling New Zealand's methamphetamine problem, says Police Minister Judith Collins, despite figures showing meth crime has more than doubled in parts of the country over the last three years.

"[Police are] doing their job really well - in fact if you look at methamphetamine seizures, they've gone up, and it's because of the amount of work going on in the sector," she says.

"But if police ignored P the charge numbers would go down, and would people be very happy with that? I don't think so at all.

"I think this is an issue that we're taking extremely seriously. It's a huge driver of crime, particularly violent crime, and dishonesty."

But the Addiction Practitioners' Association of Aoteaora New Zealand (DAPAANZ) thinks the Government isn't tackling the problem in the right way.

Figures released to Newshub reveal that in the last three years meth crime has more than doubled in Northland, the East Coast, and Canterbury.

In the East Coast three years ago, 58 P charges were laid. By last year that had almost tripled to 153.

Ms Collins says big busts made this year are proof authorities are taking action.

And public tip-offs, like the one which led a massive seizure on Northland's 90 Mile Beach, are proof the public have faith in police, she says.

"Police get a lot of their intelligence is through tip-offs, because the public has so much confidence and trust in police."

New Zealand's problem has changed from meth being manufactured in the country to it being imported ready-made, Ms Collins says.

"We don't have precursors in the shops, chemist shops for instance, and a lot of it is now being brought in."

Australia, Canada, the UK and the US also have the same issue, she says.

"This stuff is being made in industrial-sized batches in India, China, Thailand, Mexico - it's coming in and it's coming right down the East Coast particularly, through Australia and New Zealand.

"We're having to work with international agencies," she says. "[New Zealand police] are now based around the world to actually make sure we get this drug."

"Actually it would be great if they all stopped bringing it into the country."

In Christchurch, Ms Collins says police have had great success cracking down on the Rebels motorcycle gang, which was a big meth distributor.

Last week the Government pledged $15 million to combat the rise of the drug, money which will be split across the police force, Customs, Corrections and health.

"One of the things that money is going towards is rehab," says Ms Collins. "But also we need to have enough people who offer that rehab and do it properly.

"One of the things I'd like to do is get a lot more messaging out there [about how addictive P is], and that's where I think the Drug Foundation can step up, is about the dangers of methamphetamine."

DAPAANZ's Sue Paton says not enough money is being focused on treatment and rehabilitation, and we should be focused on reducing demand for the drug.

"We're about to spend a $1 billion building another 1800 prison beds because our prison numbers are growing at a ridiculous rate, largely because of drug offences, and $15 million has just been set aside to combat methamphetamine," she says.

"Most of this will go on police initiatives with very little set aside for treatment. Meanwhile the Government lacks any focused strategy for increasing access to treatment or reducing waitlist times."

Contrary to Ms Collins, Ms Paton thinks the rise in arrests is a negative thing.

"It's clear we're doing something seriously wrong," she says.

"There's good evidence that treatment, prevention and rehabilitation are effective, but it seems our Government just doesn't want to know."